It’s a game for the Nintendo DS handhelds. A strategy RPG originating from Japan (the story is also set in Japan).
You follow the lives of three kids. One of them is you, the other two are your friends. Your cousin gives you three COMPs, DS-like devices. They’re no regular COMPs though. They have bene homebrewed and can run a demon-summoning program. Tokyo gets locked down due to demons on the lose and you have to find a way out.

That’s by far the whole storyline, and it’s a terrible summary, too. It’s the best I could do for now, sorry.
But really, it’s pretty epic. You form teams consisting of a human and up to two demons. You place them on allowed spots on the field and the battle starts. Abuse strengths and weaknesses and defeat the enemy.

I’m a sucker for strategy RPGs, so this really got me. Also love how you get lots of oppertunities to give answers of your own, or at least select an answer. As far as I know it just slightly affects the dialogue you’re having, and nothing storyline related, so that’s a bitof a letdown. Still, I believe you can choose not to meet certain people at certain times. I wonder what effect those decisions have on the storyline.